Multi-access intraprocedural embolic protection device

ABSTRACT

An embolic protection device comprises a tubular filter body attached to a sheath. The tubular filter body has an open upstream end and a generally closed downstream end for capturing emboli. A self-opening passage through the emboli capture end of the tubular filter body allows multiple catheters to be advanced from the sheath or otherwise into the filter body simultaneously or sequentially. The sheath is attached to a peripheral support structure near the emboli capture end of the filter body to facilitate deployment and retrieval of the filter body through a restraining delivery catheter.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of Ser. No. 17/858,637 (AttorneyDocket No. 41959-711.301), filed Jul. 6, 2022, which is a continuationof U.S. patent application Ser. No. 16/808,859 (Attorney Docket No.41959-711.401), filed Mar. 4, 2020, now U.S. Pat. No. 11,399,927, whichis a divisional of U.S. patent application Ser. No. 15/137,924 (AttorneyDocket No. 41959-711.201), filed Apr. 25, 2016, now U.S. patentapplication Ser. No. 10,617,509, which claims the benefit of U.S.Provisional Application Nos. 62/272,643 (Attorney Docket No.41959-711.101), filed Dec. 29, 2015; 62/294,018 (Attorney Docket No.41959-711.102), filed Feb. 11, 2016; and 62/297,053 (Attorney Docket No.41959-712.101), filed Feb. 18, 2016, the full disclosures of which areincorporated herein by reference.

The disclosure of this application is also related to the disclosures ofcommonly owned, co-pending U.S. patent application Ser. Nos. 14/537,814(Attorney Docket No. 41959-707.201), filed Nov. 10, 2014 and U.S. patentapplication Ser. No. 13/735,864 (Attorney Docket No. 41959-705.201),filed Jan. 7, 2013, the full disclosures of which are incorporatedherein by reference. Priority is not being claimed from the applicationslisted in this paragraph.

BACKGROUND OF THE INVENTION

1. Field of the Invention. The present invention relates generally tomedical devices and methods and more particularly to apparatus andmethods for providing embolic protection to a patient's aortic archvessels during cardiac surgery and interventional cardiology procedures.

Cerebral embolism is a known complication of cardiac surgery,cardiopulmonary bypass, and catheter-based interventional cardiology andelectrophysiology procedures. Embolic particles, including thrombus,atheroma, and lipids, may become dislodged by surgical or cathetermanipulations, enter the bloodstream, and “embolize” to the brain orother vital organs downstream. Cerebral embolism can lead toneuropsychological deficits, stroke, and even death. Other organsdownstream of an embolic release can also be damaged, resulting indiminished function or organ failure.

Of particular interest to the present invention, a number of proceduresare performed on aortic valves using catheters advanced over thepatient's aortic arch. Valvuloplasty procedures have been performed formany years and use high pressure balloons advanced over the aortic archto disrupt calcifications on the aortic valve. Such procedures present asignificant risk of emboli release to the cerebral arteries. Morerecently, percutaneous aortic valve replacement (PAVR) procedures, alsoknown as transcatheter aortic valve implantation (TAVI) procedures ortranscatheter aortic valve replacement (TAVR) procedures, have beenapproved, and their use has become widespread. While offering manypatient benefits, they also present a significant risk of embolirelease, particularly when performed transvascularly with cathetersintroduced over the aortic arch.

The prevention of embolism in these and other procedures would benefitpatients and improve the outcome of many surgical procedures. Given thatpotential emboli are often dislodged during catheter-based proceduresthat involve more than one access site and more than one proceduraldevice, it would be advantageous to deploy an embolic protection systemthat provides multiple access paths through or beyond the protectiondevice to perform diagnostic and interventional procedures with multiplecatheters. It would be further advantageous to integrate the embolicprotection system on a sheath that is being used to perform theprocedure, such as is used with an angiographic diagnostic catheter, atranscatheter valve delivery system, and an electrophysiology catheter.

U.S. Patent Publ. No. 2015/0066075, commonly assigned herewith,describes an introducer sheath, intended specifically for use invalvuloplasty and TAVR procedure, which addresses some of theshortcomings of prior embolic protection sheath access devices. The '075sheath includes embolic protection elements and is suitable foradvancing a contrast or other small catheter through the sheath and asecond catheter through port formed in a filter. While a significantimprovement over previous embolic protection access sheathes havingfeatures, particular designs of the '075 access can be challenging todeploy and retrieve, can lose small amounts of emboli, and can have arelatively large profile during deployment.

Therefore, it would be desirable to provide improved devices, systems,and methods for preventing embolism during cardiac and other proceduresperformed over the aortic arch. Such devices, systems, and methodsshould offer less complicated deployment protocols, should have arelatively low profile when being deployed, and should afford reliableand efficient emboli containment at all times during a procedure. Atleast some of these objectives will be met by the inventions describedherein.

2. Description of the Background Art. U.S. Patent Publ. No. 2015/0066075has been described above. Other filters and devices for preventingcerebral embolism are described in U.S. Patent Publ. Nos. 2013/0178891;2010/0312268; 2006/0287668; 2005/0010246; 2005/0283186; 2004/0215167;and 2003/0100940; PCT Publ. WO/2004/019817; and U.S. Pat. Nos.8,114,114; 7,232,453; 6,712,834; 6,537,297; 6,499,487; 6,371,935;6,361,545; 6,258,120; 6,254,563; 6,245,012; 6,139,517; and 5,769,819.

SUMMARY OF THE INVENTION

The present invention provides methods, systems, and devices forcollecting emboli and in particular for preventing the release of emboliinto the cerebral vasculature during the performance of interventionalprocedures in a patient's aorta, including aortic valve replacement,aortic valve valvuloplasty, and the like, where there is a risk ofemboli being released into the aortic side vessels, including thebrachiocephalic artery, the left carotid artery, and the left subclavianartery. The present invention provides embolic protection devices,tubular filter bodies, and systems and methods for placement of thedevices and filters through the descending aorta and over the aorticarch to inhibit emboli release into the aortic side branch vessels whileallowing simultaneous access to the aortic valve by one, two, three ormore interventional and/or diagnostic catheters being introduced fromthe descending aorta, typically by conventional unilateral or bilateralfemoral artery access.

The embolic protection devices include a filter body and a deploymentcatheter body connected to the filter body. The filter body typicallycomprises a tubular porous mesh material and has an open upstream end toallow the entry of blood flow and emboli and an open downstream end toallow entry of at least one working catheter and usually two or moreworking catheters simultaneously. The deployment catheter body isdirectly or indirectly coupled to the open downstream end of the filterbody, where upstream and downstream refer to the direction of bloodflow, e.g. downstream is toward the descending aorta and away from theheart and aortic arch. At least one self-sealing port or passage isprovided in an interior of the filter body, and the deployment catheterbody typically has at least one lumen to provide at least one accessroute to an interior of the tubular filter body for introducing adiagnostic, interventional or other working catheter through theself-sealing port. Preferably, one or more additional working cathetersmay be introduced through the same self-sealing passage simultaneouslyor sequentially with a first catheter introduced through the sheath.Additional self-sealing or other catheter-access ports could be includedto provide other, parallel access routes through the filter body but arenot usually necessary as the self-sealing passage will typically have adiameter which is sufficiently expandable to allow the simultaneouspassage of two or more catheters while being able to close to blockemboli release when no catheter is present. Other axially alignedself-sealing catheter-access ports could also be included to provideadditional emboli capture chambers within the filter body.

In a first specific aspect of the present invention, an embolicprotection device comprises a filter body formed from a tubular porousmesh material and having an open upstream end and an open downstreamend. A self-sealing port is spaced inwardly from each of the ends, andthe self-sealing port includes an expandable opening configured toconform to at least one working catheter passing therethrough. Aradially collapsible support is coupled to a periphery of the downstreamend of the filter body, and a catheter body having a distal end iscoupled to the radially collapsible support, where distal refers to adirection on the device away from the operator, i.e., further away fromthe portion of the device that is outside the body. Similarly, the termproximal refers to a direction of the device closer to the operator,i.e., nearer to the portion of the device that is outside the body. Adelivery sheath has a lumen configured to receive and radially constrainthe filter body such that the catheter body may be distally advancedrelative to the delivery sheath to release the filter body fromconstraint and to allow the filter body to radially expand with thesupport circumscribing the downstream end of the filter body. In thisway, the catheter body may be distally advanced and proximally retractedrelative to the delivery sheath to move the assembly of the support andfilter body out of and into the lumen of the delivery sheath. Inparticular, when advanced out of the delivery sheath, the support willopen to assist in deployment of the downstream end of the filter bodyand, when retracted back into the delivery sheath, the support willclose to collapse the downstream end of the filter body prior to thefilter body being drawn into the lumen.

In particular embodiments, the filter body has an open cylindricalchamber disposed between a downstream end of the port and the downstreamend of the filter body. The port may comprise a wall portion up thetubular porous mesh material, where the wall portion folds, inverts, orotherwise deflects radially inwardly as other wall portions expand whenreleased from radial constraint from the delivery sheath. In still otherparticular embodiments, the wall portion inverts to form a port having aconical opening or base on a downstream side. For example, the invertedwall portion of the tubular porous mesh material may have a resilientlyclosed sleeve portion extending in an upstream direction from an apex ofthe conical opening or base which defines the expandable opening of theport.

In still further particular embodiments, the radially collapsiblesupport may comprise a loop secured around the periphery of thedownstream end of the filter body. The loop may be connected to a tetherwhich passes through a deployment lumen in the catheter body. The loopmay be configured as a lasso to allow the tether to draw the open end ofthe filter body closed prior to drawing the filter body into the lumenof the delivery sheath. Alternatively, the radially collapsible supportmay comprise a scaffold having an open end coupled to the periphery ofthe downstream end of the filter body and a constricted end coupled tothe distal end of the catheter body.

In still other particular embodiments of the present invention, thecatheter body will include a lumen for receiving at least one workingcatheter so that the working catheter may be advanced through the lumenand into the open downstream end of the filter body and then through theport. The catheter body may further include at least one additionallumen for receiving a tether attached to the radially collapsiblesupport. Additional lumens may also be provided for other purposes.

In a second specific aspect of the present invention, a luminal embolicapture device comprises a filter body formed from a tubular porous meshmaterial and having an open upstream end, an open downstream end, and atleast a first port spaced inwardly from each of the ends. The portcomprises an expandable opening configured to conform to at least oneworking catheter passing therethrough, and the filter body will have atleast an open cylindrical chamber at its downstream end and an opencylindrical chamber at its upstream end, where the port is disposedtherebetween. The emboli capture device may further comprise a catheterbody having a distal end coupled to the downstream end of the filterbody.

In specific embodiments, the porous mesh material comprises a fabric ofknitted, braided, woven, or nonwoven fibers, filaments, or wires havinga pore size chosen to prevent emboli over a predetermined size frompassing therethrough. In many embodiments, the fabric will bedouble-walled over at least a portion of the tubular mesh, and theporous mesh material may be made of a resilient metal, a polymermaterial, a malleable material, a plastically deformable material, ashape-memory material, or combinations thereof. In further specificcases, the porous mesh material may have an anti-thrombogenic coating onits surface, and the pore size will typically be in the range from about1 mm to about 0.1 mm. An exemplary porous mesh material comprises adouble layer braid formed from 288 individual wires, including acombination of 276 Nitinol® (nickel-titanium alloy) wires and 12tantalum wires, each wire being 0.002 inch in diameter, formed to afinal double-layer mesh diameter of between 20 mm and 40 mm.

In further particular embodiments, the at least first port is formedfrom or comprises a wall portion of the tubular porous mesh material.The wall portion is formed or shaped, e.g. being thermally shaped andset, so that the port folds or closes radially inwardly as other wallportions expand when released from constraint. The wall portion willtypically be pre-shaped to invert to form a port with a conical openingon a downstream side, and, typically, a closed sleeve portion extendingin an upstream direction from an apex of the conical opening whichdefines the expandable opening of the port. In alternative embodiments,the port may be defined by a wall portion of the tubular porous meshwhich is constricted, pinched, or otherwise closed radially inwardly butwill open in response to the passage of the working catheter(s)therethrough. In a particular embodiment, in additional to the upstreamand downstream chambers, the filter body may have one or more open“central” cylindrical chambers between a downstream end of the first orother port and an upstream end of the second or other port.

In a third specific aspect of the present invention, a clot retrievalsystem comprises an embolic protection device as just described incombination with a clot retrieval working catheter having a clot capturedistal end, where the clot retrieval working catheter is configured todraw retrieved clot in a downstream direction through an open upstreamend on the filter body into a central chamber.

In a fourth specific aspect, the present invention provides a method foradvancing a working catheter into and/or over a patient's aortic arch. Acylindrical filter body formed at least partly from a porous mesh isprovided. The cylindrical filter body defines a collection chamber foremboli and has an open upstream end, an open downstream end, aself-sealing port spaced inwardly from each of the ends, and a radiallycollapsible support coupled to a periphery of the downstream end of thefilter body. A deployment catheter which carries and constrains thecylindrical filter body is advanced to a downstream side of the aorticarch while the filter body remains in its radially constrainedconfiguration, typically with a previously placed delivery sheath. Thecylindrical filter body is radially expanded so that a wall of theporous mesh covers the patient's aortic side or branch vessels and theopen upstream end of the filter body faces the patient's heart. Bloodflows into an interior of the filter body through the open upstream end,and emboli collect in the collection chamber. As the filter body isdeployed, the support radially expands to hold the downstream end of thefilter body open, and blood flowing through the porous mesh of thefilter body and into the aortic side vessels is substantially embolifree. After the filter body is deployed, a first working catheter can beadvanced through the open downstream end of the filter body and throughthe self-sealing port and toward the heart. Optionally, a second workingcatheter may be advanced through the open downstream end of the filterbody and through the self-sealing port toward the heart, eithersimultaneously or sequentially with placement of the first workingcatheter.

In particular embodiments, a first diagnostic or interventionalprocedure may be performed with the first working catheter and a seconddiagnostic or interventional procedure may be performed with the secondcatheter. It will be appreciated that third, fourth, and additionalworking catheters may also be introduced and advanced eithersimultaneously or sequentially with other working catheters.

The first working catheter is typically introduced through a lumen inthe deployment catheter, and the second working catheter may beintroduced in parallel to the deployment catheter. In this way, thedelivery profile of the deployment catheter can be minimized. In oneexample, a first working catheter will be used to introduce contrastmedia to an interventional site while a second working catheter willperform an interventional procedure at that site. More specifically, theinterventional procedure may comprise delivery of a prosthetic aorticvalve, performance of valvuloplasty, or the like.

In still further particular embodiments, the deployment catheter isadvanced while present in a delivery sheath which radially constrainsthe cylindrical filter body. Radially expanding the cylindrical filterbody may comprise proximally retracting the delivery sheath relative tothe deployment catheter. Typically, the radially expanded filter body isretrieved by retracting the deployment catheter to collapse the radiallycollapsible support to close the open downstream end of the filter anddraw the closed downstream end of the filter body into the deliverysheath. More specifically, retracting the deployment catheter tocollapse the radially collapsible support may comprise retracting atether present in the lumen of the deployment catheter to first collapsethe radially collapsible support to close the downstream end of thefilter body and then to retract the deployment catheter to draw theclosed downstream end of the filter body into the delivery sheath.

In still further embodiments, the filter may contain one or more supportstructures or wires that provide longitudinal stiffness to the device toprevent compression or movement of the filter during the procedure. Suchwires or structures may extend the full length of the device or only fora portion of its length and such wires or structures shall be eitherfixedly or slidably attached to the access sheath.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a partially exploded view of a first embodiment of an embolicprotection device constructed in accordance with the principles of thepresent invention.

FIG. 2 is a detailed view of the connection between a filter body and adeployment catheter body of the embolic protection device of FIG. 1 .

FIG. 3 is a detailed view shown in partial section of a tether structurewhich connects a downstream end of the filter body to an upstream ordistal end of the catheter body of the embolic protection device of FIG.1 .

FIGS. 4 and 5 illustrate use of a peel-away catheter for introducing thefilter body of the embolic protection device of FIG. 1 into a port of adelivery sheath for advancement to an aortic arch in accordance with theprinciples of the methods of the present invention.

FIG. 6 illustrates the contralateral positioning of the delivery sheathfor placement of the embolic protection device and a separatetranscatheter aortic valve replacement (TAVR) catheter as would be usedfor placement of a prosthetic heart valve using the embolic protectiondevice of the present invention.

FIGS. 7A-7ZZ illustrate positioning of the embolic protection device ofthe present invention over a patient's aortic arch and delivery of aprosthetic aortic valve through the embolic protection device inaccordance with the methods of the present invention.

FIGS. 8A-8E illustrate a number of different folding patterns for atubular porous mesh material in order to form filter bodies useful inthe embodiments of the present invention.

FIG. 9 illustrates a second embodiment of an embolic protection deviceconstructed in accordance with the principles of the present invention.

FIG. 10 illustrates a third embodiment of an embolic protection deviceconstructed in accordance with the principles of the present invention.

FIG. 11 illustrates a fourth embodiment of an embolic protection deviceconstructed in accordance with the principles of the present invention.

FIG. 12 illustrates use of the device of FIG. 11 for introducing asecond working catheter through a self-sealing port of the embolicprotection device of FIG. 11 .

FIGS. 13A-13C illustrate a fifth embodiment of an embolic protectiondevice constructed in accordance with the principles of the presentinvention, and further show a step wise formation of a self-sealingvalve in a filter body of the device.

FIG. 14 illustrates placement of a sixth embodiment of an embolicprotection device constructed in accordance with the principles of thepresent invention over a patient's aortic arch.

FIGS. 15A-15C illustrate different folding patterns which can be used toprovide self-sealing ports in the filter bodies of the presentinvention.

FIGS. 16A-16E illustrate the use of a filter body similar to that shownin FIG. 15B for capturing clot in a second exemplary method of thepresent invention.

DETAILED DESCRIPTION OF THE INVENTION

As shown in FIGS. 1-3 , an embolic protection device 10 constructed inaccordance with the principles of the present invention comprises afilter body 12 having an open upstream end 16 and an open downstream end18. The filter body 12 is typically formed from a porous mesh material,more typically a tubular porous mesh material which is preformed to havea self-sealing port 20 with an expandable opening 22 located between theopen upstream end 16 and the open downstream end 18, typically closer tothe open downstream end as illustrated. Specific folding patterns forthe filter body 12 are described below with reference to FIGS. 8A-8E,and several exemplary alternative folding patterns are described belowin connection with FIGS. 15A-15C.

A radially expandable/collapsible support 24 is secured at the opendownstream end 18 of the filter body 12, as best seen in FIG. 2 . Theradially collapsible support 24 may comprise a tube 34 (FIG. 3 ) havinga pull wire 36 with a loop 37 formed at its distal end. The loop 37 issecured about the periphery of the open downstream end 18 of the filterbody 12 so that it may act as a “lasso” or a “purse-string” componentfor opening and closing the open downstream end 18. In particular, byproximally retracting the pull wire 36 within the tube 34 (to the rightin FIG. 3 ), the loop 37 may be closed. Conversely, by distallyadvancing the pull wire 36 relative to the tube 34, the loop 37 may beopen. As described in more detail below, by axially advancing andretracting the tether structure 32, the filter body 12 may be positionedrelative to a deployment catheter body 28.

The self-sealing port 20 of the filter body 12 divides the filter bodyinto an upstream cylindrical chamber 26A and a downstream cylindricalchamber 26B. Each of the chambers 26A and 26B will be generally freefrom internal structure, and the self-sealing port 20 will act to dividethe two chambers and, in particular, to prevent passage of emboli whichmay enter the upstream chamber 26A into or beyond the downstream chamber26B. The downstream cylindrical chamber 26B acts to receive andfacilitate introduction of working catheters into and through theself-sealing port 20 in order to perform interventional proceduresupstream of the filter body 12 when the filter body is deployed in theaorta or other blood vessels.

The deployment catheter body 28 has a distal end 30 and at least a firstlumen 38 for carrying the tether structure 32 and a second lumen 40which serves as a working lumen for introducing interventional orworking catheters therethrough, such as TAVR catheters for deployingprosthetic aortic valves as will be described in detail below.

A proximal or control hub 29 is coupled to a proximal end 31 of thedeployment catheter body 28. A proximal end 33 of the tether structure32 extends from the control hub 29 and allows a user to manipulate thetether structure, and including both axial retraction and advancement ofthe tether structure as well as opening and closing of the loop 37. Thecontrol hub 29 also has a port 35 which opens to the second lumen 40 inthe catheter body 28 for allowing passage of guide wires, workingcatheters, and the like.

The filter body 12 will typically be self-expanding. By“self-expanding,” it is meant that the filter body will be resilient andhave a normally open or expanded configuration when free from radialand/or axial constraint. By either radially contracting or axiallyextending the filter body, the diameter or profile of the filter bodywill be reduced so that it can be intravascularly introduced to aworking site in the patient's vasculature, typically over the aorticarch but optionally in other locations as well. Additionally, byradially collapsing and/or axially extending the filter body, theself-sealing port within the filter body will be unfolded and axiallyextended.

The self-sealing port 20 will be self-forming, typically having aconical base 56 and an extending sleeve 58, as shown in FIG. 1 . Theself-sealing port 20 will have at structure which is formed by foldingand inverting the generally tubular structure of the filter body as theradius of the filter body increases and the length of the filter bodyaxially shortens. The necessary fold lines will be pre-formed into thefilter body, typically by heat treatment. In exemplary embodiments, thefilter body will be formed as a Nitinol® (nickel-titanium alloy) thinwire mesh which will be formed to have the fold lines described in moredetail with reference to FIGS. 8A-8E below. These pre-formed fold lineswill allow the filter body to be axially elongated and radiallycollapsed to have a low profile during delivery, typically having adelivery diameter below 12 Fr (French), often below 10 Fr. Conversely,the filter body will typically open to an unconstrained width ordiameter above 5 mm, often above 15 mm more often above 25 mm, andtypically in the range from 25 mm to 40 mm. As will be described in moredetail below, the filter body 12 will be introduced in its low profileconfiguration through a delivery sheath 42 which has been pre-placed inthe patient's artery, typically through the femoral artery over theaortic arch. In order to advance the filter body into the deliverysheath 42, however, it is necessary to temporarily constrain theself-expanding filter body 12. This may be achieved using a peel-awaysheath 48, as shown in FIGS. 4 and 5 . The filter body 12 is axiallyelongated and radially collapsed and drawn into the lumen of thepeel-away sheath 48, as shown in FIG. 4 . The peel-away sheath coversthe filter body 12 with the catheter body 28 extending from a proximalend of the peel-away sheath 48. The temporary assembly of the peel-awaysheath and the catheter body 28 can be introduced over a guidewirestructure 46 which has been pre-placed through a distal port 44 of thedelivery sheath 42, as shown in FIG. 4 , with the sheath then beingadvanced through the distal port 44, as shown in FIG. 5 . Once thedistal end of the filter body 12 has been introduced through the port 44into the proximal end of the delivery sheath 42, the peel-away sheathmay be removed as the filter body continues to be introduced into thedelivery sheath 42. To facilitate delivery, each of the delivery sheath42 and the peel-away sheath 48 may have ports to allow the introductionof fluids into their lumens.

As shown in FIG. 6 , the delivery sheath 42 will be introduced throughthe patient's groin into a femoral artery and up and over the aorticarch in a conventional manner. A second sheath 50, typically forintroducing a TAVR or other interventional or working catheter, will bepositioned in the contralateral femoral artery for introducing theworking catheter up the aorta and over the aortic arch AA in parallel tothe delivery sheath 42. Such positioning will be intended for prostheticvalve placement or other interventional procedures on the patient's Pheart H.

Referring now to FIGS. 7A-7ZZ, a particular protocol for introducing aprosthetic valve PV into the patient's native aortic valve AV will bedescribed. As shown in FIG. 7A, the delivery sheath 42 is initiallyplaced over the guidewire structure 46 as just described with referenceto FIG. 6 . The catheter body 28 is then advanced through the innerlumen of the delivery sheath 42 such that the radially constrainedfilter body 12 approaches the open distal end 52 of the delivery sheath.

By then holding the catheter body 28 relatively still or stationary andretracting the delivery sheath 42 in a proximal direction, i.e., awayfrom the patient's aortic valve AV, the distal end of the filter body 12will be released from constraint so that the tubular porous mesh 14 willbegin to radially expand, as shown in FIG. 7B. The delivery sheath 42continues to be proximally retracted, as shown FIG. 7C, so that thetubular porous mesh 14 expands and engages the inner wall of theascending aorta immediately above the aortic valve AV. As shown in FIG.7D, the delivery sheath 42 continues to be proximally withdrawn,allowing the tubular porous mesh 14 to continue to expand and to begincovering the branch vessels BV, with relative full deployment of theupstream cylindrical chamber 26A of the filter body 12 shown in FIG. 7E.As also shown in FIG. 7E, the self-sealing port structure 20 is at itsvery initial stages of being formed, with further formation being shownin FIG. 7F.

As shown in FIG. 7G, the conical base 56 of what will become theself-sealing port 20 is largely formed, and the downstream cylindricalchamber 26B begins to form as shown in FIG. 7H. The downstreamcylindrical chamber 26B is largely formed as shown in FIG. 7I while theself-sealing port 20 is just beginning to form. By then advancing thecatheter body 28 in the direction toward the aortic valve AV, as shownin FIG. 7J, a narrowed segment of the tubular porous mesh 14 will beginto invert to form the sleeve structure 58 of the port 20. As alsoapparent in FIGS. 7I and 7J, the radially collapsible support 24, in theform of the loop 37, opens to open and support the open distal end ofthe downstream cylindrical chamber 26. It is this support structure 24which allows the catheter body 28 to manipulate the downstream portionof the filter body 12 so that the downstream cylindrical chamber 26B canbe advanced distally or toward the aortic valve AV relative to theupstream cylindrical chamber 26A. The radially expandable/collapsiblesupport 24A will also be useful when retracting the filter body 12 atthe end of the procedure, as will be described in more detail below.

The fully deployed self-sealing port 20 is shown in FIG. 7K with thesleeve 58 defining the expandable opening 22 and the conical base 58facilitating introduction of catheters from the downstream end, as shownin more detail below.

In specific examples, the guidewire structure 46 may include an externalsupport tube which may be retracted and withdrawn to leave the guidewirein place, as shown in FIG. 7L. A diagnostic catheter 60 may then beadvanced over the guidewire 46, as shown in FIG. 7M typically being usedfor angiography. This port 20 will expand to accommodate the diameter ofthe diagnostic catheter 60 while sealing around the catheter to preventany emboli from passing through the port.

After withdrawing the diagnostic catheter 60, another guidewire 62 maybe introduced for advancing a TAVR delivery catheter 64, as shown inFIG. 7N. The first catheter structure 46 will typically be left in placealthough it is not visible in FIG. 7N. The TAVR delivery catheter 64 isthen advanced over the patient's aortic arch AA, as shown in FIG. 7O,until it passes through the native aortic valve AV, as shown in FIG. 7P.A prosthetic valve PV will then be released from the TAVR catheter 64,as shown in FIG. 7Q. It should be appreciated that during theadvancement of the TAVR catheter 64 over the aortic arch AA, and inparticular during release of the prosthetic valve PV, there is asubstantial risk of emboli being released as the aortic arch and theaortic valve AV may be heavily calcified. If such emboli are present,they will be carried over the aortic arch and through open upstream end16 of the filter body 12 so that they enter and are contained within theupper cylindrical chamber 26A. In particular, the tubular porous mesh 14will prevent emboli of any significant size from entering any of thebranch vessels BV while allowing blood flow into these vessels. Thesleeve 58 of the self-sealing port 20 will conform to and seal aroundthe exterior of the TAVR delivery catheter 64, thus inhibiting orpreventing accidental passage of emboli through the port while it isexpanded to permit catheter passage.

After the prosthetic valve PV has been released, as shown in FIG. 7Q,the TAVR delivery catheter 64 will be proximally retracted over theguidewire 62, as shown in FIG. 7R. The first guidewire 46 is also shownin FIG. 7R. The TAVR delivery catheter 64 continues to be withdrawn andexits through the self-sealing port 20 which then closes over theguidewire 46, as shown in FIG. 7S and 7T. The TAVR guidewire 62 is thenpulled back through the aorta, as shown in FIG. 7T.

After the TAVR catheter 64 and guidewire 62 have been withdrawn, theprosthetic valve PV is in place and it is necessary to withdraw thefilter body 12 from the aortic arch AA. As shown in FIG. 7U and 7V, thetether structure 32 is manipulated to close the loop 37 of the radiallycollapsible support 24. In addition to closing the loop 37, the proximalend of the filter structure 12 is drawn to the distal end of thecatheter body 28, and the catheter body 28 retracted to draw the filterbody into the delivery sheath 42, as shown in FIG. 7W.

The catheter body 28 continues to be proximally withdrawn so that itpulls the downstream cylindrical chamber 26 into the delivery sheath 42,as shown in FIG. 7X, and continues to be proximally withdrawn until theentire filter body 12 is drawn into the delivery sheath 42, as shown inFIGS. 7Y, 7Z, and 7ZZ. The filter body and all emboli contained thereinare then safely captured within the delivery sheath 42, and the deliverysheath 42 may be withdrawn from the patient and the procedure may becompleted in a conventional manner.

The porous filter mesh material may comprise a variety of knitted, wovenor nonwoven fibers, filaments or wires, and will have a pore size chosento allow blood to pass through but prevent emboli above a certain sizefrom passing through. Suitable materials include resilient metals, suchas shape and heat memory alloys, polymers, and combinations thereof, andthe materials may optionally have an anti-thrombogenic coating (such asheparin) on their surfaces. The filter meshes may further incorporatematerials and structures to enhance the radiopacity of the filter body.Exemplary materials include gold, platinum, palladium, or tantalum, andother metals having a greater radiopacity than the resilient metals, aswell as radiopaque coatings or fillings. In other cases, the resilientmetal filaments or wires may be served with thinner, more radiopaquewires or filaments.

The filter body may be constructed in discrete sections that areattached together, but will more typically be formed from a continuouscylindrical mesh structure that is narrowed or folded in sections toform the specific design features, typically consisting of a single suchfolded tubular mesh structure. Forming the device from one continuouscylindrical mesh allows the filter body to be axially stretched fordeployment and/or retrieval, thereby reducing the profile of the filter.Another advantage of a filter formed from a single, continuous tabulatemesh material is that it will contain only smooth, rounded edges. Suchedges minimize friction and snagging with catheters and the proceduraltools being introduced through the filters.

The self-sealing port may be configured as a conical structure with theaccess port at its narrow end, typically formed by a sleeve as describedpreviously. In other embodiments, as illustrated below, the self-sealingport may be a simple narrowing of the cylindrical structure, e.g. aself-closing neck region which seal around catheters and other toolsintroduced therethrough. Whatever the particular geometry, theself-sealing port can be formed by shape-setting a larger, tubular orcylindrical mesh in a reduced diameter via heat treatment or coldforming. In addition, other embodiments of the self-sealing port can bestraight, contain a twist, be corrugated, have a flattened section, orpossess other features that assist in its ability to close aroundprocedural devices sufficiently to inhibit or prevent emboli frompassing through when a catheter is in place. In still other embodiments,the filter body may contain two or more such self-expanding portstructures. The port 20 may accommodate a single device (such as aguidewire, catheter, valve delivery system, pacing lead, etc.), twodevices or more than two devices simultaneously and can expand andcontract to maintain a sufficient seal around multiple devices asneeded. Further, such devices can be introduced through the downstreamcylindrical chamber 26B and into the port 20 by way of the working lumen40 of the catheter body 28 or directly by way of a second sheath 50 inan alternative access site, or in some combination thereof.

Referring now to FIGS. 8A-8E, a number of different patterns for formingthe tubular porous mesh material 14 of the present invention into afilter body 12 having the self-sealing port 20 between the upstreamcylindrical chamber 26A and the downstream cylindrical chamber 26B areillustrated. It will be appreciated that each of the structures in FIGS.8A-8B begins with a single layer tube of a mesh material as justdescribed. In the configuration of FIG. 8A, the tubular structure isfirst folded into a bi-layer structure having a fold 14A in its middle.The bi-layer structure is then folded back upon itself and inverted inorder to form the illustrated filter body 12 a having a structure whichis then heat set in the fully radially expanded configuration.

The filter body 12 b of FIG. 8B similarly begins as a bi-layer tubularmesh with a single fold 14B at one end. The bi-layer structure is thenfolded similarly to the pattern of FIG. 8B, except that the open end ofcylindrical chamber 26A is folded in an inwardly inverted pattern ratherthan in a simple fold-back pattern as shown in FIG. 8A.

The filter body 12 c illustrated in FIG. 8C is again similar in mostrespects to the fold pattern of filter 12 a of FIG. 8A, except that theopen end of the upstream cylindrical chamber 26A has an inner layerfolded over an outer layer to form a distal cuff, where the inner layerterminates within the folded-back outer layer.

The filter body 12 d illustrated in FIG. 8D is in many ways the inverseof that filter body 12 a of FIG. 8A. A single fold 14D in the originalsingle-layer tubular cylinder is located at the open end of the upstreamcylindrical chamber 26A. The open downstream end of downstream chamber26B is folded back on itself to form a cuff structure.

Filter body 12 e as illustrated in FIG. 8E is the simplest structure ofall where folding of the downstream cylindrical chamber 26B is similarto that in FIGS. 8A-8C, but the open end of the upstream cylindricalchamber 26A terminates with the inner and outer layers open and notfolded back at all.

FIG. 9 illustrates a first alternative embodiment of an embolicprotection device 70 constructed in accordance with the principles ofthe present invention. A filter body 72 has an open upstream end 74 anda closed downstream end 76. A self-sealing port 78 is formed in theclosed downstream end 76, and a support structure 82 is attached at adownstream end of the filter body. The support structure 82 comprises apair of struts and can be made of a material (such as a shape memoryalloy) that can be compressed for delivery and expanded in situ by therelease of a constraining sheath 86. The support is fixedly or movablyattached to a deployment catheter body 80 via a collar 84. A distal orupstream end of the catheter body 80 passes through the closed end 76 ofthe filter body 72 adjacent to the self-sealing port 78.

FIG. 10 illustrates a second alternative embodiment of an embolicprotection device 90 constructed in accordance with the principles ofthe present invention. A filter body 92 with a closed downstream end 93is attached to a deployment catheter body by fully circumferentialsupport structure 96. The support structure 96 comprises “stent-like”diamond elements over the region where the support structured overlapsand is attached to the mesh material of the filter 92. The supportstructure 96 is fixedly or movably attached to a deployment catheterbody 94 via a collar 100 and a plurality of struts 98. A distal orupstream end of the catheter body 94 passes through the closed end 93 ofthe filter body 92 adjacent to a self-sealing port 99.

FIGS. 11 and 12 illustrate a third alternate embodiment of an embolicprotection device 102 having a conical mesh self-sealing port 108 in aclosed end 106 of a filter body 104. A deployment catheter body 114 isattached by a collar 116. A delivery sheath 118 is provided for deliveryand traction of the filter body 104. In FIG. 11 , a distal or upstreamend of the catheter body 114 is disposed through the self-sealing port108 and provides an introductory lumen or other path through the portadjacent to the self-sealing port 108. In FIG. 12 , a TAVR delivery orother working catheter is introduced through the self-sealing port inparallel to the catheter body 114. The periphery of the self-sealingport 108 will be sufficiently compliant (elastic) to conform to and sealagainst both catheters simultaneously.

FIGS. 13A-13C illustrate a fourth alternative embodiment of an embolicprotection device 130 constructed in accordance with the principles ofthe present invention. A filter body 132 comprises a double layer ofmesh throughout most of the filter, with an additional layer or cuff 150(for a total of three layers) at a downstream end to increase theanchoring strength of the filter in this portion of the device. FIG. 13Ashows the embolic protection device 130 in its relaxed configuration,while FIGS. 13B and 13C show the embolic protection device 130 as it isaxially stretched in the direction of arrows 146 into a delivery orretrieval configuration. Since a self-sealing port 134 and other devicefeatures are integrally or monolithically formed within a continuouscylindrical mesh structure, these features effectively disappear whenthe filter body 132 is fully stretched out in the axial direction. Thisability to stretch out and eliminate internal structure minimizes thedevice profile. The construction of the filter from one continuouscylindrical surface also avoids manufacturing complexity and maintains asmooth contact surface throughout the device to reduce the friction ofprocedural tools passing through the filter. The filter body is attachedto a deployment catheter body 144 by a stent-like peripheral supportstructure 140 which overlaps or overlies a downstream cylindricalchamber 139 of the filter body 132. The self-sealing port 134 maycomprise a conical base 136 and a sleeve 138 generally as describedpreviously.

FIG. 14 illustrates the embolic protection device 130 deployed over apatient's aortic arch to protect the branch vessels as an interventionalcatheter is delivered in an upstream direction through the self-sealingport 134 to perform a procedure, such as valvuloplasty or TAVR, at theaortic valve AV.

FIGS. 15A-15C shows alternative configurations of the filter body of thepresent invention. FIG. 15A shows a filter body 160 comprising anupstream cylindrical chamber 162 and a downstream cylindrical chamber164 separated by a simple narrowing or neck 166 formed in thecylindrical mesh material. The cylindrical mesh material may besingle-walled, double-walled, have more than two layers over some or allof the wall area, or combinations thereof, and this filter bodyconfiguration can be combined in most or all of the embodiments of theembolic protection devices of the present invention describedpreviously.

FIG. 15B shows a filter body 170 comprising an upstream cylindricalchamber 172, a central cylindrical chamber 174, and a downstreamcylindrical chamber 178 separated by a necks 180 and 182, respectively.It will be appreciated that such multiple cylindrical chambers could beseparated by any of the self-closing port structures describedpreviously. The downstream end of the downstream cylindrical chamber 178may be gathered or closed, as illustrated, and the filter body 170 witha closed downstream end may find particular use in the clot captureconfigurations described in FIGS. 16A-16E below. As with previousembodiments, the cylindrical mesh material of filter body 170 may besingle-walled, double-walled, have more than two layers, or becombinations thereof, and multi-chamber filter body configurations canbe combined in most or all of the embodiments of the embolic protectiondevices of the present invention described previously, although thedownstream end of the downstream chamber will have to be opened.

FIG. 15C shows a filter body 200 comprising an upstream cylindricalchamber 202, a central cylindrical chamber 204, and a downstreamcylindrical chamber 206 separated by a neck 208 and a self-sealing port210, respectively. The downstream end of the downstream cylindricalchamber 206 is open, and the multi-chamber filter body 200 can becombined in most or all of the embodiments of the embolic protectiondevices of the present invention described previously. The cylindricalmesh material of filter body 200 may be single-walled, double-walled,have more than two layers, or be combinations thereof.

FIGS. 16A-16E show a specific procedural using the filter body 170 ofFIG. 15B for capturing clot and/or thrombus in a cardiac, peripheral, orcerebral blood vessel BV. Such devices and protocols will beparticularly useful for clot/thrombus retrieval in a cranial vessel totreat acute ischemic stroke. As shown in FIG. 16A, the gathered end 179of the filter body 170 is attached to a distal end of a deploymentcatheter 210, and the catheter 210 is advanced through a microcatheter230 (FIG. 16E). A clot capture catheter 220, such as a Merci® retrievercatheter, having a clot capture element 222, such as a helical tip atits distal end is advanced through the catheter 220, the filter body170, and into the clot/thrombus THR, as shown in FIG. 16B. The clotcapture catheter 220 is then pulled proximally to draw the clot/thrombusTHR through neck 180 into the central chamber 174, as shown in FIGS.16B-16D. After the clot/thrombus THR is in the central chamber 174, thechance that it will be lost from the filter is greatly reduced, and anyemboli which might escape through the necks 180 and 182 will likely becaptured in the upstream and downstream cylindrical chambers 178 and172, respectively. The upstream neck 180 will be configured to stretchopen to allow the clot retrieval device and the ensnared thrombus andclot to pass through, and to close after the clot and/or thrombus arefully enclosed within the central cylindrical chamber 174. Any debristhat may come loose from the clot and thrombus is contained by thefully-closed necks 180 and 182 (FIG. 16D), the assembly of the clotretriever 220, the filter body 170, and catheter body 220 may be safelywithdrawn through the microcatheter 230.

Modification of the above-described assemblies and methods for carryingout the invention, combinations between different variations aspracticable, and variations of aspects of the invention that are obviousto those of skill in the art are intended to be within the scope of theinvention disclosure.

What is claimed is:
 1. An embolic protection device, said devicecomprising: a filter body comprising a tubular porous mesh having anopen upstream end, an open downstream end, and a port disposed inside ofthe tubular porous mesh on an upstream side of the open downstream, saidport comprising an expandable opening configured to conform to at leastone working catheter passing therethrough; a radially collapsiblesupport coupled to a periphery of the downstream end of the filter body;a catheter body having a distal end coupled to the radially collapsiblesupport; and a delivery sheath having a lumen configured to receive andradially constrain the filter body; wherein the catheter body may bedistally advanced relative to the delivery sheath to release the filterbody from constraint and to allow the filter body to radially expandwith the support circumscribing the downstream end of the filter bodyand wherein the catheter body may be distally retracted relative to thedelivery sheath to pull the support and filter body back into the lumenof the delivery sheath such that the support radially collapses thedownstream end of the filter body prior to the filter body being drawninto the lumen; and wherein the port comprises an inverted wall portionof the tubular porous mesh material which is inverted radially inwardlyto the inside of the tubular porous mesh.
 2. An embolic protectiondevice as in claim 1, wherein the radially collapsible support comprisesa loop secured around the periphery of the downstream end of the filterbody.
 3. An embolic protection device as in claim 2, wherein thecatheter body has at least one deployment lumen which receives a tetherattached to the radially collapsible support loop.
 4. An embolicprotection device as in claim 3, wherein the loop is configured as alasso to allow the tether to draw the open downstream end of the filterbody closed prior to drawing the filter body into the lumen of thedelivery sheath.
 5. An embolic protection device as in claim 1, whereinthe radially collapsible support comprises a scaffold having an open endcoupled to the periphery of the downstream end of the filter body and aconstricted end coupled to the distal end of the catheter body.
 6. Anembolic protection device as in claim 1, wherein the open upstream endof the filter body is defined by a periphery of the open upstreamchamber.
 7. An embolic protection device as in claim 1, wherein theinverted wall portion of the tubular porous mesh has a resilientlyclosed sleeve portion extending in an upstream direction from an apex ofthe conical opening which defines the expandable opening of the port. 8.An embolic protection device as in claim 1, wherein the inverted wallportion of the tubular porous mesh material is collapsed to define theexpandable opening of the port.
 9. An embolic protection device as inclaim 1, wherein the catheter body includes at least a working catheterlumen for advancing a working catheter therethrough, into the opendownstream end of the filter body, and through the port.
 10. An embolicprotection device as in claim 9, wherein the catheter body furtherincludes at least a deployment lumen which receives a tether attached tothe radially collapsible support.
 11. An embolic protection device as inclaim 1, wherein the port comprises a self-sealing port.
 12. An embolicprotection device as in claim 1, wherein the port is spaced inwardlyfrom each of said ends of the filter body.
 13. An embolic protectiondevice as in claim 1, wherein the port inverts radially inwardly asother wall portions expand when released from radial constraint from thedelivery sheath.
 14. An embolic protection device as in claim 1, whereinthe inverted wall portion forms the port with a conical opening on thedownstream side.